1. Field of the Invention
The present invention relates to an apparatus for and a method of mounting electronic parts on a circuit board.
2. Description of Related Art
Apparatuses for mounting electronic parts on a circuit board in general include an image reader performing position recognition of the electronic parts. Positioning of electronic parts for mounting the electronic parts at predetermined mounting positions on a circuit board is carried out on the basis of the results of the position recognition. As image readers, such as a line sensor in which a plurality of pixels are linearly arranged and an area sensor in which a plurality of pixels are arranged in a two-dimensional lattice form are used. By having an optical image formed on the photodetecting section of such an image reader, each pixel thereof comes to build thereon an electric charge corresponding to the optical image. By allowing such electric charges to be sequentially output as electric signals (image signals), image data representative of an electronic part can be obtained.
However, since it has been practiced in conventional mounting apparatuses to have image signals sequentially output from all of the pixels constituting the photodetecting section, image signals from pixels unnecessary for position recognition have also been output. Therefore, the time required for reading an image of an electronic part has been prolonged and this has made it difficult to shorten the time required for position recognition of an electronic part.